The SILCC project: IV. Impact of dissociating and ionizing radiation on the interstellar medium and Hα emission as a tracer of the star formation rate
We present three-dimensional radiation-hydrodynamical simulations of the impact of stellar winds, photoelectric heating, photodissociating and photoionizing radiation, and supernovae on the chemical composition and star formation in a stratified disc model. This is followed by a sink-based model for...
Saved in:
| Main Authors: | , , , |
|---|---|
| Format: | Article (Journal) |
| Language: | English |
| Published: |
10 December 2016
|
| In: |
Monthly notices of the Royal Astronomical Society
Year: 2017, Volume: 466, Issue: 3, Pages: 3293-3308 |
| ISSN: | 1365-2966 |
| DOI: | 10.1093/mnras/stw3216 |
| Online Access: | Verlag, kostenfrei, Volltext: http://dx.doi.org/10.1093/mnras/stw3216
|
| Author Notes: | Thomas Peters, Thorsten Naab, Stefanie Walch, Simon C.O. Glover, Philipp Girichidis, Eric Pellegrini, Ralf S. Klessen, Richard Wünsch, Andrea Gatto and Christian Baczynski |
| Summary: | We present three-dimensional radiation-hydrodynamical simulations of the impact of stellar winds, photoelectric heating, photodissociating and photoionizing radiation, and supernovae on the chemical composition and star formation in a stratified disc model. This is followed by a sink-based model for star clusters with populations of individual massive stars. Stellar winds and ionizing radiation regulate the star formation rate at a factor of ∼10 below the simulation with only supernova feedback due to their immediate impact on the ambient interstellar medium after star formation. Ionizing radiation (with winds and supernovae) significantly reduces the ambient densities for most supernova explosions to ρ < 10−25 g cm−3, compared to 10−23g cm−3 for the model with only winds and supernovae. Radiation from massive stars reduces the amount of molecular hydrogen and increases the neutral hydrogen mass and volume filling fraction. Only this model results in a molecular gas depletion time-scale of 2 Gyr and shows the best agreement with observations. In the radiative models, the Hα emission is dominated by radiative recombination as opposed to collisional excitation (the dominant emission in non-radiative models), which only contributes ∼1-10 per cent to the total Hα emission. Individual massive stars (M ≥ 30 M⊙) with short lifetimes are responsible for significant fluctuations in the Hα luminosities. The corresponding inferred star formation rates can underestimate the true instantaneous star formation rate by a factor of ∼10. |
|---|---|
| Item Description: | Gesehen am 23.10.2017 |
| Physical Description: | Online Resource |
| ISSN: | 1365-2966 |
| DOI: | 10.1093/mnras/stw3216 |